1. Field of the Invention
This invention relates to fasteners and mountings and is particularly, but not exclusively, concerned with the fastening and mounting of decorative wooden strip mouldings.
2. Description of the Prior Art
The term mounting is used herein to embrace disparate fasteners, fixtures and fittings for attaching one element--of whatever shape--to another, however achieved.
In the fastener art an enormous variety of disparate devices, mechanisms and arrangements are known, ranging from, say, automobile internal or external trim snap-action clip fittings, through building structural supports, such as expanding wall plugs, to cabinet making and joinery blind-joints.
It is generally desirable to provide a secure, often selectively-releasable or detachable, attachment mechanism, which will be reasonably simple in overall design and thus economical to manufacture.
In the particular circumstance of so-called `blind-fixing`--that is a fixture or fitting which is not visible from a `front` orientation of an element held by the fixture, it is generally desirable to avoid penetrating the thickness or depth of that element by a fixture passing from one (front) surface to an opposite (rear) surface. To do otherwise requires some form of precision fabricated filler or blanking piece and a precision aperture in the element itself.
In the finishing art in the building, construction, decoration, refurbishment or architectural trades, it has long been known to use pre-fabricated finishing strip material, whether of wood, plaster or otherwise, in order to enhance the finished appearance after basic construction is completed. Often, advantage is taken of the presence of such a finishing strip--for want of a better expression--to cover or disguise an unwanted or otherwise visually intrusive feature, and indeed to shield or protect a conduit, trunking or tube, providing, say, electrical, water, drainage or heating services.
Although such finishing materials may represent a more costeffective means of achieving a desired overall standard of general finish than would be feasible with what might be termed `craftsman standards` of `on-site` hand finishing of individual component elements, for example along abutting join of two panels, or at a corner site, or junction between walls and ceiling or floor, where misalignment between intersecting and supposedly planar and rectilinear surfaces becomes most apparent, they nevertheless are expensive in themselves--not least because of the intricacies in surface profile and high standards of surface finish inherent in their construction.
Moreover, it does not necessarily follow that such finishing strips will entirely `de-skill` the fitment or installation of the strips themselves. In particular, if, as is commonly the case, no special provision is made in the design of the strip mouldings for their installation, for example, mounting upon a surface, it may be necessary to resort to relatively crude fastening techniques; even for example, piercing the critical surface finish to penetrate the body of the strip with a screw or the like and afterwards in-filling with proprietary filler or blanking dowels.
This essentially means interfering with and thus usually spoiling the finish surface so carefully produced, simply in order to install the surface in the desired location and thereafter, seeking to rectify the damage done with techniques which cannot match the standards of finish of the original strip, which is generally fabricated off-site on special-purpose machines.
If special fasteners or mountings are provided, for example clips and the like, they have often still been visible when the strip is mounted, for example, by embracing the overall strip cross-section, or are otherwise noticeable, for example by keeping the strip marginally away from the mounting surface, by virtue of the fastener depth itself.
Further the fasteners may not allow ready removal of the strip once fitted--should this be desired.
An elaborate fastener is expensive to manufacture and thus, if a large number of such fasteners is required, so the expense is multiplied, to the extent that the user may be encouraged to revert to ordinary fasteners driven through the body of the strip as previously discussed.
Thus the fastener spacing is a crucial factor in determining the number of fasteners required for a given length of strip and this is in turn reflected in the security of grip or hold afforded by an individual fastening. Too secure a hold will result in the strip being difficult to remove, for example by simply prising apart from the mounting surface, without causing surface damaging, i.e., marring the very improved appearance which the fastener is intended to impart.
On the other hand, too loose a fastening could allow the strip to become inadvertently dislodged, for example by casual contact.
Of course, non-removability may be accepted as a limitation, but particularly for (hard)wood finishing strips, removal could facilitate separate decoration of surrounding and indeed abutting areas, for example painting or papering the mounting surface itself.
Indeed, in the very original fitting operation, temporary positioning and subsequent repositioning may be required, for which purpose a disconnectable fastening or fitting is clearly advantageous.
It is also desirable that the fitting and fastening arrangement facilitates the marking out and aligning operation for determining the strip position. That is if the strip can be offered up to the mounting surface, preliminary temporary markings made, and the fasteners positioned from those markings, whereafter the strip will automatically be aligned without distortion--for example because the fastenings have been mounted in a curve rather than a straight line.
It is advantageous if the fastener is a one-piece element, with no separate complementary part required on the strip itself, and if it can be fabricated of synthetic plastics material, so that when the initial tooling cost is recovered, the marginal cost of producing subsequent fasteners is substantially reduced.
The overall requirement for a low-cost, simple, secure, reusable, fastening is not easily met in practice.
The term `strip` used herein, embraces any shape of article to be mounted, but is especially concerned with elongate objects--that is whose cross-section is small in relation to their length, and more particularly, where the cross-section is uniform over the length.
The fastener should lend itself to the alignment of multiple abutting strips.
Symmetry of the fastener means that the mounting orientation is reversible, ie. the fastener cannot effectively be mounted upside down, so that the fasteners may be positioned more readily.
For convenience, the fasteners should be mountable at any position along a strip.
No special outer profile of the strip, which would change the appearance of the front of the strip locally, should be required for the fastener location.
No special mounting or tightening steps or tools should be necessary.
The strip should lie with its rear face flush with the mounting surface.
Any re-shaping of the strip should be uniform along its length and otherwise not unduly complex to produce.
To an extent the fastener could be self-locking--that is to say, at least initial attempts at withdrawal or removal of the strip would be resisted in a manner reinforcing the interengagement of the fastener and the strip, but possibly (although not essentially) allowing disengagement upon further applied force.
The fastener should accommodate some deformation or misalignment of the strip, but should otherwise promote retention of alignment of the strip.
The fastening action should be achieved by a straightforward relative movement of the strip and fastener--preferably a linear translational movement, rather than a rotational or twisting action.